UMass chemists clear hurdle for solar energy storage

AMHERST — Chemists have been trying for years to make a new type of battery that can store solar energy in chemical bonds rather than electrons, and release the energy on demand as heat instead of electricity — addressing the need for long-term, stable, efficient storage of solar power.

Now, chemists at the University of Massachusetts report that they have solved one of the major hurdles in the field by developing a polymer-based system. This method can yield energy storage density — the amount of energy stored — more than two times higher than previous polymer systems. Details appear in the current issue of Scientific Reports​​​​​​.

UMass researchers said previous high energy storage density achieved in a polymeric system was in the range of 200 Joules per gram, while the new system is able to reach an average of 510 Joules per gram, with a maximum of 690.

Lead researcher Dhandapani Venkataraman said, “Theory says that we should be able to achieve 800 Joules per gram, but nobody could do it. This paper reports that we’ve reached one of the highest energy densities stored per gram in a polymeric system, and how we did it.”

The authors said applications for the new technology include solar pads that collect and store energy by day then heat food, living spaces, clothing or blankets at night. They noted that this approach will be especially valuable in areas where there is no access to a power grid.

Venkataraman said his group’s accomplishment would probably not have been possible without earlier theoretical work by Jeffrey Grossman at MIT.

Venkataraman worked with Ph.D. student and first author Seung Pyo Jeong, Ph.D. students Larry Renna, Connor Boyle and others.

The chemists plan to follow up this discovery with work to solve some practical problems related to charging the system, so they have not made a battery yet.